The present invention relates to a regeneration device, and more particularly, to a regeneration device of an exhaust gas purification filter and a filter regeneration method.
The number of automobiles has been increasing drastically. The amount of gas discharged from the internal combustion engines has also increased drastically in proportion to the increase in the number of automobiles. The various substances included in the exhaust gas of a diesel engine have caused pollution, which has a severe impact on the world environment. Further, there have been recent reports on research results stating that fine particulates included in the exhaust gas cause allergic disorders and a decrease in the number of sperms. Accordingly, the removal of the particulates from the exhaust gas is a problem that must be immediately coped with by mankind.
Under such circumstances, various types of exhaust gas purification apparatuses have been proposed. An exhaust gas purification apparatus includes a plurality of filters that eliminate particulates discharged from internal combustion engines, such as diesel engines. When a filter is used for a long time, particulates are deposited in the filter. The deposited filter increases the load on the engine. Thus, the particulates must be eliminated.
Presently, when the particulates on a filter approach a maximum collection amount, a switch valve switches the filter through which exhaust gas flows. The filter through which the exhaust gas no longer flows is heated by an electric heater until it reaches a temperature at which the particulates are ignited. The filer is regenerated by burning and removing the particulates.
However, in the conventional purification apparatus, the electric heater heats the filter even if the initial temperature of the filter that is to be regenerated is lower than the temperature of the engine exhaust gas. This prolongs the filter regeneration time. For example, when the diesel engine is running continuously, the filter temperature is about the same as the exhaust gas temperature. However, when the diesel engine is stopped over a long period, the filter temperature is low, and the increase rate of the filter temperature is low. Thus, much time is required for the particulates to reach the ignitable temperature. This increases the regenerating time. In addition, the prolonged regenerating time lengthens the activation time of the electric heater, increases power consumption, and lowers the durability of the electric heater.
It is an object of the present invention to provide a regeneration device of an exhaust gas purification filter and a filter regeneration method that reduces the regenerating time of a filter.
A first perspective of the present invention is a regeneration device of a filter in an exhaust gas purification apparatus of an internal combustion engine. The exhaust gas purification apparatus includes a plurality of casings arranged in a plurality of branch exhaust pipes of the internal combustion engine, a plurality of filters respectively accommodated in the casings, a plurality of heaters for heating the filters, and a plurality of switch valves arranged downstream to the casings to switch a flow route of exhaust gas. The regeneration device includes a plurality of first temperature detectors arranged in the casings to detect the temperature in each casing, and a second temperature detector for detecting the temperature of the exhaust gas. A processor is connected to the first temperature detectors and the second temperature detector. The processor compares the temperature of the exhaust gas and the temperature of at least one of the casings, opens the associated switch valve based on the comparison result, and preheats at least one of the filters with the exhaust gas. Accordingly, the heat of the exhaust gas increases the temperature of the filter from the initial temperature in a sudden manner and reduces the filter regeneration time.
A second perspective of the present invention is a method for regenerating a filter in an exhaust gas purification apparatus of an internal combustion engine. The regeneration method includes the steps of detecting the temperature of the exhaust gas, detecting the temperature of at least one of the casings, comparing the temperature of the exhaust gas and the temperature of the at least one of the casings, supplying exhaust gas to the at least one of the casings to preheat the associated filter with the heat of the exhaust gas by opening the associated switch valve when the comparison result is greater than a predetermined value, stopping the supply of exhaust gas to the at least one casing after the preheating is completed, and activating the associated heater to further heat the associated filter.
A third perspective of the present invention is a filter regeneration program executed by a computer in an exhaust gas purification apparatus. The program includes the steps of comparing the temperature of the exhaust gas and the temperature of at least one of the casings with the computer, supplying exhaust gas to the at least one of the casings to preheat the associated filter with the heat of the exhaust gas by opening the associated switch valve with the computer when the comparison result is greater than a predetermined value, stopping the supply of exhaust gas to the at least one casing with the computer after the preheating is completed, and activating the associated heater with the computer to further heat the associated filter.
A fourth perspective of the present invention is a computer-readable recording medium recording a program for regenerating a filter in an exhaust gas purification apparatus. The program includes the steps of comparing the temperature of the exhaust gas and the temperature of at least one of the casings, supplying exhaust gas to the at least one of the casings to preheat the associated filter with the heat of the exhaust gas by opening the associated switch valve when the comparison result is greater than a predetermined value, stopping the supply of exhaust gas to the at least one casing after the preheating is completed, and activating the associated heater with the computer to further heat the associated filter.